Global irrigation contribution to wheat and maize yield

Summary, in English

Irrigation is the largest sector of human water use and an important option for increasing crop production and reducing drought impacts. However, the potential for irrigation to contribute to global crop yields remains uncertain. Here, we quantify this contribution for wheat and maize at global scale by developing a Bayesian framework integrating empirical estimates and gridded global crop models on new maps of the relative difference between attainable rainfed and irrigated yield (ΔY). At global scale, ΔY is 34 ± 9% for wheat and 22 ± 13% for maize, with large spatial differences driven more by patterns of precipitation than that of evaporative demand. Comparing irrigation demands with renewable water supply, we find 30–47% of contemporary rainfed agriculture of wheat and maize cannot achieve yield gap closure utilizing current river discharge, unless more water diversion projects are set in place, putting into question the potential of irrigation to mitigate climate change impacts.

• Author: Xuhui Wang; Christoph Müller; Joshua Elliot; Nathaniel D. Mueller; Philippe Ciais; Jonas Jägermeyr; James Gerber; Patrice Dumas; Chenzhi Wang; Hui Yang; Laurent Li; Delphine Deryng; Christian Folberth; Wenfeng Liu; David Makowski; Stefan Olin; Thomas A.M. Pugh; Ashwan Reddy; Erwin Schmid; Sujong Jeong; Feng Zhou; Shilong Piao
• Department/s: Dept of Physical Geography and Ecosystem Science; eSSENCE: The e-Science Collaboration; MERGE: ModElling the Regional and Global Earth system; BECC: Biodiversity and Ecosystem services in a Changing Climate
• Publishing year: 2021
• Language: English
• Publication/Series: Nature Communications
• Volume: 12
• Issue: 1
• Links: http://dx.doi.org/10.1038/s41467-021-21498-5
• Document type: Journal article
• Publisher: Nature Publishing Group
• Topic: Agricultural Science
• Status: Published
• ISBN/ISSN/Other: ISSN: 2041-1723